OXCF950_06 Datasheet, PDF (39/66 Pages) Oxford Semiconductor – low cost asynchronous 16-bit PC card or Compact Flash UART device

OXFORD SEMICONDUCTOR, INC.
OXCF950 rev B DATA SHEET
6.6 Interrupts & Sleep Mode
The serial interrupt on the OXCF950 is routed through to
the OXCF950 interrupt control, regardless of MCR[3].
6.6.1 Interrupt Enable Register ‘IER’
Serial channel interrupts are enabled using the Interrupt
Enable Register (‘IER’).
IER[0]: Receiver data available interrupt mask
logic 0 ⇒Disable the receiver ready interrupt.
logic 1 ⇒Enable the receiver ready interrupt.
IER[1]: Transmitter empty interrupt mask
logic 0 ⇒Disable the transmitter empty interrupt.
logic 1 ⇒Enable the transmitter empty interrupt.
IER[2]: Receiver status interrupt
Normal mode:
logic 0 ⇒ Disable the receiver status interrupt.
logic 1 ⇒ Enable the receiver status interrupt.
9-bit data mode:
logic 0 ⇒ Disable receiver status and address bit
interrupt.
logic 1 ⇒ Enable receiver status and address bit
interrupt.
In 9-bit mode (i.e. when NMR[0] is set) reception of a
character with the address-bit (9^th bit) set can generate a
level 1 interrupt if IER[2] is set.
IER[3]: Modem status interrupt mask
logic 0 ⇒ Disable the modem status interrupt.
logic 1 ⇒ Enable the modem status interrupt.
IER[4]: Sleep mode
logic 0 ⇒ Disable sleep mode.
logic 1 ⇒ Enable sleep mode whereby the internal clock
of the channel is switched off.
Sleep mode is described in section 6.6.4.
IER[5]: Special character interrupt mask or alternate
sleep mode
9-bit data framing mode:
logic 0 ⇒ Disable the special character receive interrupt.
logic 1 ⇒ Enable the special character receive interrupt.
In 9-bit data mode, The receiver can detect up to four
special characters programmed in Special Character 1 to
4. When IER[5] is set, a level 5 interrupt is asserted when a
match is detected.
650/950 modes (non-9-bit data framing):
logic 0 ⇒ Disable the special character receive interrupt.
logic 1 ⇒ Enable the special character receive interrupt.
In 16C650 compatible mode when the device is in
Enhanced mode (EFR[4]=1), this bit enables the detection
of special characters. It enables both the detection of
XOFF characters (when in-band flow control is enabled via
EFR[3:0]) and the detection of the XOFF2 special
character (when enabled via EFR[5]).
750 mode (non-9-bit data framing):
logic 0 ⇒ Disable alternate sleep mode.
logic 1 ⇒ Enable alternate sleep mode whereby the
internal clock of the channel is switched off.
In 16C750 compatible mode (i.e. non-Enhanced mode),
this bit is used an alternate sleep mode and has the same
effect as IER[4]. (See section 6.6.4)
IER[6]: RTS interrupt mask
logic 0 ⇒ Disable the RTS interrupt.
logic 1 ⇒ Enable the RTS interrupt.
This enable is only operative in Enhanced mode
(EFR[4]=1). In non-Enhanced mode, RTS interrupt is
permanently enabled.
IER[7]: CTS interrupt mask
logic 0 ⇒ Disable the CTS interrupt.
logic 1 ⇒ Enable the CTS interrupt.
This enable is only operative in Enhanced mode
(EFR[4]=1). In non-Enhanced mode, CTS interrupt is
permanently enabled.
DS-0027 Feb 06
External—Free Release
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